After several TV appearances over the course of a week, George Zimmerman’s older brother Robert Zimmerman Jr. launched aggressive Twitter posts targeted at the lawyers of Trayvon Martin.

He singled out lawyer Natalie Jackson in particular, who he blames for the negative media portrayal.

“I hope God grants you a long life so you live to repent for what you have done,” he wrote on a tweet to her on Monday.

The older Zimmerman has been has been protesting the innocence of his brother, who is accused of murdering unarmed teenager Trayvon Martin. The Zimmerman family has become proactive in defending their brother, appearing on shows like Piers Morgan, and other Spanish speaking stations like Univision, in an attempt to change the image of the family. With her face hidden, Zimmerman’s mother Gladys insisted that her son is not a racist.

She cited a homeless African-American man who George allegedly discovered beaten and left unconscious. “Nobody defended him except for my son,” Mrs. Zimmerman told Morgan.

“I believe in the judicial system,” says Mrs. Zimmerman. “I believe from the beginning that, you know, he is innocent, and I mean, the media had played a big role against my son. They had portrayed him in a bad — bad picture. But there is justice in America, and I believe in justice.”

But the Robert Zimmerman tweets highlight a problem for George Zimmerman’s defense team.

His attorney, Mark O’Mara, told the Miami Heraldthat “he cringed when he saw the rant and that the media tour had gone ahead without George Zimmerman’s knowledge.”

O’Mara’s says Robert Zimmerman should, “be careful with my case.”

“I have been cautious with how we act in this case and now someone with the same last name who does not act with the same constraints is out there — and I have no control over him,” added O’Mara

“They felt it was time to let the world know that the Zimmerman family is a good family. That goal is a noble goal. But they do have to be sensitive to the environment in which we are telling this story. No matter what, George is still at risk here. And we still have a dead young man — that’s fresh on everyone‘s mind. That frustrates me.”

As recently as last month, Zimmerman’s best friend published a book meant to be a new account of the Zimmerman case. It was riddled with errors and is now on the evidence list.